3 years ago

Need Help With Physical Ed

Physics

2 answers:

Dimas [21]3 years ago

8 0

which of the following is not a barrier to physical activity it is fear of injury I think.

mote1985 [20]3 years ago

5 0

I believe it’s fear of injury

You might be interested in

Which are base units used in the metric system? Check all that apply.

Shtirlitz [24]

Liters

Grams

Degrees Celsius

The other answer choices are from the imperial system

7 0

3 years ago

Read 2 more answers

A sodium atom will absorb light with a wavelength near 589 nm if the light is within 10 MHz of the resonant frequency. The atomi

Troyanec [42]

Answer:

i)20369 photons

ii) 40 ps

Explanation:

Momentum of one Sodium atom:

$P=m*v =600m/s*23amu*\frac{1 kg}{6.02*10^{23}amu}\\P=2.29*10^{-23}kgm/s$

In other to stop it, it must absorb the same momentum in photons:

$P=2.29*10^{-23}kgm/s=n_{photons}*\frac{h_{planck}}{\lambda}\\=n*\frac{6.63*10^{-34}}{589*10^{-9}} \\==>n=20369 photons$

Now, for the minimun time, we use the speed of light and the wavelength. For the n photons:

$t=n*T=n*\frac{\lambda}{c} =20369*\frac{589nm}{3*10^{8}m/s}=4*10^{-11} second=40 ps$

7 0

3 years ago

Your friend tells you that a shiny element has to be a metal. Do you agreed? Explain your reasoning

Svetradugi [14.3K]

no i dont agree, because a glass bowl is shiny but its not a metal. just because some metals are shiny doesnt make all metals shiny

3 0

3 years ago

Read 2 more answers

Help, anyone?? please:/

NeTakaya

A,E,C,B,D is the order

5 0

3 years ago

In Trial III, a different, looser, spring is used; its force constant is 23.1 N/m. The suspended mass is the same as the one in

cricket20 [7]

Answer:

T=0.827s

Explanation:

The period of a spring can be calculated with the equation

$T=2\pi w$

But we know as well that w is given by,

$w=\sqrt{\frac{k}{m}}$

Replacing,

$w=\frac{2\pi}{T}= \sqrt{\frac{k}{m}}\\T=2\pi\sqrt{\frac{k}{m}}\\T=2\pi\sqrt{\frac{0.4}{23.1}}$

So we have that

$T=0.827s$

7 0

3 years ago